Question

Consider the following:

2A -> B; deltaH = x
2B -> C; deltaH = y
What is the total enthalpy change for the reaction 4A -> C?

Answer 1

The total enthalpy change for the reaction 4A -> C can be calculated using Hess's Law by considering the enthalpy changes for the individual reactions A -> B and 2B -> C.

Step-by-step explanation:

To calculate the total enthalpy change for the reaction 4A -> C, we need to consider the enthalpy changes for the individual reactions A -> B and 2B -> C. Given that deltaH for A -> B is x and deltaH for 2B -> C is y, we can use Hess's Law to calculate the total enthalpy change:

1. First, reverse the second reaction and change the sign of deltaH to -y.
2. Then multiply the two reactions to cancel out the common intermediate (B) and sum the enthalpy changes:

2A -> B + (-y) + 4A -> C = 0 + (-y)

Therefore, the total enthalpy change for 4A -> C is -y. Make sure to substitute the specific values of x and y provided in the question to get the numerical value.